"I was trying to keep from having surgery," said Ms. Williams, 21, of Louisville, Ga., who had an abnormal Pap smear that revealed precancerous cells in her cervix. A new experimental gene therapy being studied at the Medical College of Georgia could help her do just that.

The treatment involves injecting into the patient genetic material from the human papillomavirus that can cause cervical cancer. That trains the immune system to recognize the virus and attack the precancerous cells that contain it.

The treatment had previously proved effective in 75 percent of women younger than 25, and it could eliminate the need to surgically remove the abnormal tissue and all of the potential complications that come with that, Dr. Ferris said.

In the previous study, the approach was only effective in younger women and the reason is not quite clear, Dr. Ferris said.

"We know that persistence of HPV is a bad sign," he said. "So we think that many of these younger women have rather young lesions, if you will, that seem to respond a little bit better to the immunotherapeutic agent. And older women are likely to have lesions that have been persistent for quite some time."

Avoiding the surgery, which usually involves removing the abnormal cells and some surrounding normal tissue, would have a number of advantages, Dr. Ferris said. Two studies published earlier this year found that women who underwent the most common surgical procedures were at increased risk for pre-term labor, premature membrane rupturing and other problems that could affect fertility.

"If I could give her some shots in the leg and have a three out of four chance of that girl not having to have surgery, hey, I'm all for that," Dr. Ferris said. "And I think most parents, most individuals would be very supportive of that, too."

The American Cancer Society usually doesn't comment on clinical studies until they are a little further along, but there are several therapies under development right now, said Debbie Saslow, the director of the breast and gynecologic cancer programs for the cancer society.

"Therapeutic vaccines have been in the works for a while and have been looking very promising, but none of them are ready for use," she said.

A vaccine to prevent infection from the main cancer-causing strains of HPV, which was tested by Dr. Ferris and MCG, could be available to the general public in about six months, Dr. Ferris said.

That could be big news worldwide.

While there will be about 10,000 cases and 4,000 deaths in the United States from cervical cancer, across the globe it accounts for 500,000 cases and about 250,000 deaths.

The gene therapy trial at the Medical College of Georgia is looking for women ages 13-25 who have had an abnormal Pap smear within the past three months that was not biopsied. Those with moderate to severe dysplasia or lesions can be enrolled after an evaluation. For more information, call the study coordinator at (706) 721-2535.